The present invention relates to carbon dioxide absorbers and, more particularly, to an absorber for removing carbon dioxide from respiratory gases to patients undergoing anesthesia.
Presently known carbon dioxide absorbers are typified by that disclosed in U.S. Pat. No. 3,088,810, which generally comprise upper and lower functional assemblies with one or more cannisters of a carbon dioxide absorbent material sandwiched therebetween. The exhaled respiratory gases from the patient flow from the upper assembly through the cannister or cannisters for removal of carbon dioxide therefrom and thence from the lower assembly through external connectors and an external conduit or pipe back to or through the upper assembly to a point adjacent to that from which the exhaled gases entered the upper assembly. Patient breathing tubes emanating from a face mask or the like are connected to the upper assembly at the adjacent locations where the exhaled gases entered, and the inhaled gases exited from, the upper assembly.
This type of absorber is costly and complex, requiring an inordinately large number of parts considering the relatively simple functions to be performed. For example, in addition to the external conduit between the upper and lower assemblies, an elaborate clamping arrangement is required to secure and retain the cannister or cannisters in their operative positions. The clamping structure must also be adjustable to accommodate one or two cannisters of varying sizes. The external conduit or pipe must be similarly adjustable in length, usually by means of flexible conduits or telescoping sections. Numerous machined, polished and chrome-plated connectors and fittings are also required, further adding to the cost and complexity of presently known absorbers.
Additionally, the upper and lower assemblies are usually fabricated of brass to which the fittings and connectors are generally soldered. This type of arrangement renders currently known absorbers and the parts thereof difficult to disassemble for routine cleaning, maintenance and/or repair.